Pre-Procedural Glucose Levels and the Risk for Contrast-Induced Acute Kidney Injury in Patients Undergoing Coronary Angiography

Objectives: We sought to evaluate whether pre-procedural glucose levels are associated with contrast-induced acute kidney injury (CI-AKI) after coronary angiography. Background: Although diabetes is a known risk factor for CI-AKI in patients undergoing coronary angiography, whether elevated pre-procedural glucose levels (regardless of pre-existing diabetes) are associated with higher risk for CI-AKI is unknown. Methods: We evaluated 6,358 patients with acute myocardial infarctions undergoing coronary angiography. Patients were stratified into 5 pre-procedural glucose groups: <110 mg/dl, 110 to <140 mg/dl, 140 to <170 mg/dl, 170 to <200 mg/dl, and ≥200 mg/dl. Logistic regression models were used to evaluate the relationship between glucose levels and risk for CI-AKI, first in the entire cohort and then in patients with and without established diabetes. The primary outcome was CI-AKI (≥0.3 mg/dl absolute or ≥50% relative serum creatinine increase during 48 h after the procedure). Results: The relationship between pre-procedural glucose and CI-AKI varied markedly in patients with and without diabetes. There was a strong association between glucose and CI-AKI risk in patients without diabetes (CI-AKI rates across the 5 glucose groups from lowest to highest: 8.2%, 9.9%, 12.4%, 14.9%, and 24.3%; p < 0.001), but not in patients with diabetes (20.9%, 16.1%, 16.3%, 14.8%, and 19.2%, respectively; p = 0.24; p for glucose × diabetes interaction <0.001). After adjusting for confounders (including baseline glomerular filtration rate), the relationship between higher glucose and greater CI-AKI risk persisted in patients without diabetes (odds ratios [95% confidence intervals] for glucose groups of 110 to <140 mg/dl, 140 to <170, mg/dl 170 to <200 mg/dl, and ≥200 mg/dl: 1.31 [1.00 to 1.71], 1.51 [1.11 to 2.10], 1.58 [1.03 to 2.43], and 2.14 [1.46 to 3.14] vs. glucose <110 mg/dl, respectively), but this relationship was not seen in patients with established diabetes. Conclusions: Elevated pre-procedural glucose is associated with greater risk for CI-AKI in patients without known diabetes who undergo coronary angiography in the setting of acute myocardial infarction. Measures used to prevent CI-AKI should be considered in these patients.